👉 Infection occurs when a pathogen, such as a virus, bacterium, fungus, or parasite, enters a host's body and begins to multiply or cause harm. This process starts when the pathogen breaches the body's natural barriers, like the skin or mucous membranes, often through exposure to contaminated environments, vectors (like mosquitoes), or bodily fluids. Once inside, the pathogen can attach to and invade cells, disrupt normal bodily functions, and trigger an immune response. If the host's immune system is effective, it can neutralize or eliminate the pathogen, preventing infection. However, if the pathogen overwhelms the immune system or evades detection, it can lead to disease, manifesting as symptoms ranging from mild discomfort to severe illness and even death. The body's response to infection, including inflammation and fever, aims to contain and eliminate the pathogen, but in some cases, the infection can persist or cause chronic conditions.
